1. Field of the Invention
The present invention relates to steering knuckles, and more particularly to a unique ball joint for use on a steering knuckle that lowers the height of a vehicle (i.e., a drop spindle ball joint).
2. Description of the Prior Art
It has become popular to customize vehicles by lowering the height of such vehicles relative to the ground. Lowering vehicles usually improves ride handling and is also done for aesthetic purposes, especially in light trucks. At the front end of the vehicle, lowering has been accomplished by replacing the factory-made (stock) steering knuckle provided with the new vehicle with an alternative after-market steering knuckle that lowers the vehicle height. Such vehicle-lowering steering knuckles are commonly referred to as “drop spindles.”
Factory designs for steering knuckles are constantly changing, such that new and different after-market drop spindles must also be designed. Generally speaking, a given steering knuckle is pivotally attached to an upper and lower control arm of the vehicle steering assembly. The pivotal attachments are typically made using ball joints. To lower the vehicle height at the front, it is necessary to lower the positions where the upper and lower control arms connect to the steering knuckles associated with the front wheels. Lowering these connections has the effect of raising the position of the spindle pin or shaft (wheel hub/opening) on the steering knuckle relative to those connections. The lowered control arms (raised spindle/wheel position) result in a lowered vehicle chassis height relative to the wheels.
A typical spindle (or steering knuckle) is a component of the front suspension of a vehicle, which attaches the wheel and brake assemblies to the vehicle, and allows the wheels to travel vertically (joust and rebound), turn, and rotate. The most common spindle bodies are of a cast metal configuration utilizing a press fit, metallic, machined, cylindrical shaft called a spindle pin to which the wheel bearings, brake components, and wheel are affixed. In particular, a wheel hub fits over the elongated spindle pin with bearing surfaces actually making contact with the pin. A vehicle wheel is, in turn, attached to the hub. This common type of pin and hub assembly is sometimes referred to in the industry as a “dead hub.”
In the past, drop spindles have been developed in which the position of the spindle pin shaft has been vertically changed relative to the steering knuckle body, thereby raising the position of the vehicle wheels relative to the chassis which lowers the chassis closer to the ground. This is possible because most drop spindle bodies are large enough that there is considerable space within the body, often several inches, where the position of the elongated spindle pin can be established without affecting performance.
For a variety of reasons, the manufacturers of several light trucks have recently changed the design of the steering knuckles used on these vehicles to accommodate a different kind of wheel hub assembly. The new hub assemblies are bolt-in“live” spindle hubs to which the brake and wheel assemblies are attached. The term“live” hub implies that the hub assembly, to which the brake and wheel assemblies are attached, is made up of a short shaft that rotates within, and is affixed to roller bearings that are mounted within the hub bearing housing. The hub bearing housing, in turn, is attached into the spindle body. Significantly, the bolt-in “live” hub assembly requires a much larger bore diameter to be placed within the steering knuckle body, than that previously required for a press-fit spindle pin. In addition, the bolts that attach the hub assembly to the spindle body have a set pattern which must be accommodated for. The large bore and the bolt-pattern require much more space than the press-in spindle pin designs. These differences in the design of these recent factory steering knuckles have taken away virtually all of the space previously available to accomplish the vehicle lowering function using existing drop spindle designs. Accordingly, late model trucks are unable to be lowered by traditional drop spindles.
In response the new hub assemblies design, drop spindles having inverted ball joint assemblies have been introduced to the market, such as that described in U.S. Pat. No. 6,398,240. U.S. Pat. No. 6,860,498 discloses a steering knuckle for use on a live axle application. As stated above, this, like other drop spindles on live axles succumbs to the problem of a limited capability to lower the vehicle. In addition, the disassembly, removal and replacement of the steering knuckle of the vehicle are burdensome. Such removal often requires the disassembly, removal and replacement of brake system, brake lines, and tires. Accordingly, it is desirable to minimize the cost and difficulties encountered in attempting to lower the chassis of vehicles having live wheel hubs.
Recent vehicles produced by General Motors (GM) such as the Chevy Colorado, among others, are provided with factory steering knuckles having a unique style of ball joint for attachment to the lower control arm of the steering assembly. Typical lower ball joints have a circular shaped housing that is pressed into a corresponding opening located in the lower control arm. However, instead of press-fitting the lower ball joint into such a hole, the Chevy Colorado ball joint, and others, are bolted or riveted directly into the lower control arm. It is therefore desirable to provide a drop spindle for use with such a unique lower ball joint assembly.